The health risks related to tobacco smoking are well documented. It is the single most important preventable cause of death and disability in the U.S. and causes an estimated 450,000 deaths annually. Despite widespread dissemination of this information, a significant proportion of Americans (approximately 25%) continues to or starts smoking. Worldwide it is estimated that there are over 1.2 billion tobacco smokers. The result is a huge economic burden on the population. Of particular concern is mounting evidence that exposure to environmental tobacco smoke (ETS) is also a cause of significant morbidity and mortality. Children are particularly susceptible.
Numerous strategies are being implemented to reduce childhood exposure to ETS including prohibitions on smoking in day care settings, school, and public places. Relatively few strategies have focused on the main source of ETS (i.e., smoking in the home). Identifying children by history of parental smoking becomes less productive as the parents become more aware than their smoking could cause disease in those sharing the household. Furthermore, ongoing monitoring of progress has been limited by existing technology for identifying ETS exposure. One strategy that appears to be somewhat effective, has been implemented in California, the state that has been most aggressive at reducing risk associated with ETS. As part of a comprehensive program of tobacco control, behavioral counseling of ethnically diverse, low income populations on the effects of ETS on children has been implemented and shown to significantly reduce exposure. This, however, is a short-term and limited solution to the problem. Such a strategy could be enhanced by a convenient biological measurement that could be done by any parent or child anytime, daily or many times a week at home.
Unfortunately, large number of children remain at risk of respiratory diseases, such as asthma, due to household exposure. In some instances, where asthma attacks exacerbated by ETS have been life threatening, children have had to be removed from the environment. Clearly, no single strategy is going to prevent exposure to ETS anymore than strategies to reduce smoking are going to completely stop its use.
Because it is difficult to police tobacco use in the home and the resulting exposure to ETS, it is desirable to be able to detect exposure when children are seen by healthcare professionals. ETS screening, recommended by both the CDC and AAP, should be implemented as a standard addition to the pediatric or health department exam and become a fifth vital sign.
Several techniques are available to detect tobacco byproducts, (usually the nicotine metabolite, cotinine) in blood, urine and more recently in saliva. The association between the number of cigarettes smoked per day and saliva cotinine levels has been shown to be almost linear. Similarly, the size of the house that the child of the smoker lives in is inversely related to the degree of toxic exposure. Other measurement techniques include exhaled carbon monoxide (CO) and salivary thiocyanate.
To obtain a high degree of accuracy for studying tobacco smoking, a single biomarker may not be sufficient, because smoking is a discontinuous process. Exhaled CO is a good marker of short-term exposure, while combining its measurement with either thiocyanate or cotinine provides a high correlation with smoking status, and is more accurate than self-reporting CO measurement alone. A recent study showed that cotinine levels in non-smokers who have close friends or a spouse who smoke are 1.5 times higher than those whose friends/spouse are non-smokers.
Unfortunately, these techniques are costly, time consuming, require considerable cooperation by the subject and the results are not immediately available. This reduces their value for studying smoking and ETS in individual subjects, especially children. What is needed is an inexpensive device that can detect exposure to vapors in tobacco smoke in real time. The ability to distinguish smoking or ETS from the therapeutic use of nicotine as part of a discontinuation program would also be advantageous.
Furthermore, a recent study estimates that the economic burden to payers and society of maternal smoking during pregnancy and the first year of life ranges from $1142 to $1358 per child.
Accordingly, there is a need in the art for a tobacco smoke detector for determining the exposure of children to environmental tobacco smoke (ETS) (passive smoke, sidestream smoke, second-hand smoke). Such a device would be applicable for a wide range of research related to the effects of smoking and its complications. There is also a need in the art for a detector for environmental smoke exposure capable of being used at remote locations.